A system for the conversion of liquids to gases that may be used in the context of various technologies to reduce the volume of liquids, remove and accumulate dissolved solids from liquids, produce distillates, purify water, introduce liquids into the surrounding environment or the watershed, generate expansion gases as a source of energy, or the like. Specifically, certain embodiments of the invention can be used to accelerate the evaporation of liquids that are produced from oil and gas well drilling and completion processes.
Liquids can pose significant problems with respect to transportation, storage, disposal; volume reduction, distillation, or purification; or contaminant deposition, precipitation, or accumulation, and the like. Certain of these problems have been made more acute by recent changes in federal and state laws that have generated more stringent environmental regulations with respect to storage or disposal of liquids by containment in ponds, pits, or the like. In the context of oil or gas drilling, for example, ponds or reserve pits that hold liquids (such as water generated during the drilling operations) may have to be emptied and reclaimed within 30 days of finishing the well drilling or completion process. As a result, there is an increasing market demand for cost effective liquid to gas conversion devices (liquid-gas converters), or liquid to gas conversion methods, that can be used to convert liquids to their corresponding vapors, gases, or the like (water to steam as an example), remove contaminants from liquids, reduce the volume of liquids, or prepare liquids for direct introduction into the environment or watershed.
As an example, oil or gas well drilling and completion processes may produce very large amounts of water to handle or dispose of (15,000 barrels of water is not unusual). Because liquids generated from drilling activities may contain high levels of contaminants, dissolved solids, or contain oil, gas, or other organic materials, such liquids should not be released directly into the surrounding environment or into the watershed. As such, liquids generated from well drilling operations are typically left for long periods of time to slowly evaporate. Under recently promulgated regulations, however, liquids may not remain in reserve pits to evaporate for such long periods of time, and removal of liquids from remote locations may be impossible or simply impracticable.
While other examples of liquid handling, storage, or disposal problems may be provided within the context of the oil or gas industry, other industries, including both small and large businesses, also have liquid management problems relating to conversion of liquids to gases, the reduction of liquid volume, removal of contaminants from liquids, purification of liquids, distillation of liquids, disposal of liquids, or processing of liquids for direct release into the environment, the watershed, or into sewage systems.
Because the demand for liquid-gas converters or methods of converting liquids to gases, vapors, of the like is increasing, an increasing number and variety of liquid-gas converters and methods of converting liquids to gases are now available to the consumer. Even though there is an increased number and variety of liquid-gas converters and methods for converting liquids to gas available to the consumer a number of significant problems remain unresolved with respect to converting liquids to gas, reducing the volume of liquids, the removal, deposition, or accumulation of contaminants from liquids, or the processing of liquids for direct release into the environment, watershed or sewage system.
A significant problem with existing liquid management technology may be that natural liquid evaporation rates are slow. As a result, numerous liquid-gas converters, or liquid evaporation facilitation methods, have been devised to accelerate natural evaporation or liquid to gas conversion processes. For example, efforts to facilitate the evaporation of liquids include those disclosed in U.S. Pat. No. 4,449,849, hereby incorporated by reference. The patent discloses facilitating the evaporation rate of water by spraying water from a liquid containment pond, pit, or the like into the atmosphere and recollection of the water in the pit to be re-sprayed. However, liquid spraying methods may still be too slow for operators to meet statutory reclamation deadlines, may be effected by or not work at lower temperatures, or may not meet environmental statutory or regulatory requirements. A practical problem with spraying liquids into the atmosphere to accelerate evaporation may be that wind will carry the sprayed water away from the containment area and contaminate the surrounding soil or may percolate to the underlying ground water.
Another significant problem with existing liquid management technology may be that it is incompatible or impractical to use with large volumes of liquid. Many applications require the conversion of hundreds of gallons or thousands of gallons of liquid per hour. Many liquid to gas converters, or methods of converting liquid to gas, are for individual or personal use such as facial saunas, air humidifiers, hair dressing, steam irons, or the like, as disclosed by U.S. Pat. Nos. 4,399,349; 2,343,458; 3,546,428; 3,695,066; 3,742,629; 3,511,236; 3,745,306; each hereby incorporated by reference. Even liquid to gas converters that are specifically manufactured for the reduction of substantial volumes of liquid have a practical range of application in the tens of gallons or hundreds of gallons per hour. Typically, liquid-gas converters do not have an evaporation rate exceeding 200 gallons per hour. See for example, Encon Entrainment Contained Evaporator, PSI Water Systems, Inc., http://www.evaporator.com, or Landa, Inc. http://www.landa-inc.com, each hereby incorporated by reference.
Another significant problem with existing liquid management technology may be that liquid is heated in an open container to convert the liquid to a gas. One aspect of this problem, may be that the liquid cannot be heated substantially above the boiling point of the liquid to facilitate the conversion of the liquid to a gas. As can be understood, liquids within a container are heated, certain molecules having higher than average energy escape the liquid as a gas, because molecules of higher energy are lost the remaining molecules of liquid cannot achieve substantially higher energy, as such the remaining liquid(s) maintain a temperature which does not substantially exceed its (their) respective boiling point(s). A related aspect of this problem may be that liquids heated in an open container may not be pressurized so that the temperature of the liquid may be substantially increased above the liquid(s) respective boiling point(s). Another aspect of this problem may be that liquids can be very alkaline or very acidic, depending on the concentration of substances dissolved in the liquids, and such liquids may damage the container or other components submersed in the liquid. As such, the container and other submersed components may have to be constructed of more expensive materials such as stainless steel as disclosed by U.S. Pat. No. 5,582,680, hereby incorporated by reference. See also, Encon Entrainment Contained Evaporator, PSI Water Systems, Inc., http://www.evaporator.com; and Landa, Inc., http://www.landa-inc.com.
Another significant problem with existing liquid management technology may be that substances dissolved in a liquid are difficult to isolate, accumulate, or remove from deposition surfaces. These substances may include metals, minerals, greases, oils, soaps, road film, organic compounds, or the like. For example, the xe2x80x9cSamscoxe2x80x9d water evaporator disclosed by U.S. Pat. No. 5,082,525, hereby incorporated by reference, heats liquid in a container with a serpentine heat exchanger submersed in the liquid. Substances precipitate and then accumulate in the container as liquid evaporates. These precipitates or residual solids must then be periodically removed, either automatically or manually, from the container, and the heat exchanger or other components cleaned of baked on precipitates or residual solids. Similarly, the water evaporator disclosed by U.S. Pat. No. 5,582,680 discloses that sediment and other contaminants are removed after operation.
Another significant problem with existing liquid management technology may be that the devices cannot be run continuously. One aspect of this problem can be that the device cannot process or has a reduced processing capability during the period in which it is being recharged with additional liquid. This may be due to a reduction in the temperature of the liquid to be processed or due to the fact that the unit must suspend processing entirely to be recharged. A second aspect of this problem may be that the device cannot process additional liquid because solids, precipitates, or concentrates must be removed, or the device otherwise cleaned prior to the processing of additional liquid. For example, the Landa WB series provides an auto purge feature that empties the concentrate from the evaporator device after liquid reduction and during the auto purge process additional liquid cannot be processed.
Another significant problem with existing liquid management technology may be that exhaust fans or blowers are required to move gases generated by conventional liquid-gas converters, or to move exhaust from the combustion of fuels. As can understood from U.S. Pat. No. 5,582,680 vapor flow is encouraged by a blower by drawing in outside air. Similarly, the Landa evaporators and the Encon evaporators use built in exhaust fans to move steam and combustion gases from the processing of liquids. As such, to the extent that these conventional types of liquid to gas converters have blowers, fans, or the like to move generated gas, steam, vapor, or the like, they may be more complex, require greater maintenance, be more costly to build, or be more prone to failure than less complex liquid-gas converters.
Another significant problem with existing liquid management technology may be that liquids are transported to storage or disposal sites. One aspect of this problem is the high cost of transporting the liquids from the site of generation to the storage or disposal facility. Since liquids may be continuously generated, the expense of transporting, storage, or disposal can be an ongoing expense for the life of a business, or for the life of an oil or gas well. A second aspect of this problem can be cradle-to-grave laws that may make the generator of the liquid liable for any injury or damage caused by the liquid during transportation, or even liable during the entire period of storage, disposal, or upon return to the environment or watershed.
As can be understood from the foregoing significant problems remain unresolved with respect to liquid management or liquid to gas conversion. The instant invention addresses each of the above-mentioned liquid management or liquid to gas conversion problems.
The invention comprises various embodiments of liquid to gas conversion apparatus and methods of converting liquids to their respective gases. Liquids may be generated as the residue of an industrial process, such as used cleaning solutions or liquid waste from sewage treatment, or may be generated during oil or gas drilling and carried to the surface, or may be produced naturally as precipitation, as examples. It should be understood that the invention may be used with a wide variety of liquids or mixture of liquids from numerous industrial, business, or natural sources, and even though many embodiments of the invention as described have applications related to accelerated evaporation of water, the description is not intended to limit the invention to the liquid to gas conversion of water.
Further, it should be understood that gases resulting from the application of the invention can include those molecules that are the gas phase of any substance having a liquid phase that can be dispersed and converted to gas, and such gas can also include, but are not limited to, vapor, steam, or the like. The production of such gases, vapors, steam or like resulting from use of the invention can be used in or to effect numerous applications including, but not limited to, the complete or partial conversion of a volume of liquid to a gas, liquid volume reduction, the recovery of substances associated with the liquid, the use of expanding gases for energy, the production of distillates, the preparation of liquid to be returned to the environment as gases or as liquids, or the preparation of liquid to be returned to the watershed.
Certain embodiments of the invention relate to apparatus or methods that include a liquid-gas converter. A liquid-gas converter can be understood to comprise a liquid and a sufficient amount of energy to convert a portion of the liquid to a gas. Energy may include, but is not limited to, heat, whether from the conversion of electricity, oil, gasoline, kerosene, natural gas, propane, coal, or the like. While many of the examples describe energy from the combustion of natural gas (in some cases natural gas obtained directly from gas wells that are also producing the liquid to be converted to gas, i.e. in situ) it should be understood that the invention is not limited to the use of natural gas or other conventional fuels, and even exotic forms of energy, such as microwave, nuclear fuels, or the like should be understood to be included.
As can be easily understood from the foregoing, the basic concepts of the present invention may be embodied in a variety of ways including various permutations and combinations of the various elements. As such the objects of the invention are similarly numerous and varied. It is therefore, a significant object of embodiments of the invention to convert volumes of liquid to gas. Because the liquid to gas conversion aspects of the invention can be scaled up or down, the volume of liquid converted to gas may be a few gallons of liquid per hour to thousands of gallons of liquid per hour. Specifically, as an example, an object of the invention can be to convert 15,000 barrels of water at a gas well drilling site to gas in less than thirty days.
Another significant object of the invention can be to reduce the volume of liquids, including waste water, by evaporation, and recovery of non-volatile liquids and other contaminants.
Another significant object of an embodiment of the invention can be to provide substantially continuous liquid to gas conversion. One aspect of this object of invention can be to obviate, reduce, or manage the accumulation of substances associated with the liquid during the evaporation process in a manner that does not require taking the liquid-gas converter off line for recharging with liquid, removal of accumulated precipitates, or for the cleaning of components. Another aspect of this object of the invention can be to maintain the temperature of liquids even when recharging the liquid-gas converter with additional liquid so that the level of liquid to gas conversion efficiency can be maintained.
Another significant object of an embodiment of the invention can be to pressurize the liquid prior to conversion of the liquid to a gas. One aspect of this object can be to provide sufficient pressure to prevent the liquid from being converted to gas even when the liquid is heated to temperatures that are substantially above the liquids boiling point at standard atmospheric pressure (1 atmosphere). Specifically, an aspect of this object can be to sufficiently pressurize water so that it can be heated in a range between about 100 degrees Fahrenheit to about 1000 degrees Fahrenheit.
Another significant object of an embodiment of the invention can be to generate a pressure gradient responsive to the expanding gases generated during the liquid to gas conversion, wherein the pressure gradient has sufficient change in atmospheric pressure per unit distance to move the expanding gases away from the liquid-gas converter. Specifically, one aspect of this object of the invention is to generate such pressure gradient without the use of conventional air movers such as fans, blowers, or the like.
Another significant object of an embodiment of the invention can be to remove substances associated with, or dissolved in, the liquid being converted to a gas. One aspect of this object can be to provide a deposition surface on which solids can accumulate during the conversion of liquid to a gas. A second aspect of this object of the invention can be to provide continuous removal of solids from the deposition surface during the process of converting liquids to gases.
Another significant object of an embodiment of the invention can be to produce distillates of the liquids being converted from liquid to gas. This object of the invention can include methods which condense substantially all the gas or a portion of the gas produced.
Another significant object of an embodiment of the invention can be to prepare liquids for reintroduction into the environment. One aspect of this object of the invention can be to convert liquid to gases that are then released into the atmosphere. Another aspect of this object of the invention can be to condense gases from the liquid-gas conversion for release into the surrounding watershed.
Another significant object of an embodiment of the invention can be to use the energy from the expanding gases from the liquid-gas conversion. One aspect of this object may be to drive a turbine, reciprocal to rotational energy transfer device, or the like to provide mechanical energy to operate other devices including, but not limited to, electrical generators.
Another significant object of an embodiment of the invention can be to substantially eliminate transportation, storage, or off site disposal of liquids. One aspect of this object can be to substantially eliminate costs associated with these activities. A second aspect of this object can be to substantially eliminate the liability of these activities.
Another significant object of an embodiment of the invention can be to provide a portable liquid to gas converter that can be used on site to convert liquids produced during the drilling of oil or gas wells, or during completion processes, to gases that can be released into the atmosphere or liquids that can be introduced into the surrounding watershed.
Another significant object of an embodiment of the invention can be to use natural gas produced at a well head at a low enough volume or pressure during the liquid-gas conversion process such that it has essentially no effect on the ongoing production rates of the well.
Yet another object of an embodiment of the invention can be to provide a method of accelerated water evaporation which may be environmentally acceptable from both a regulatory and a consumers perspective.
Still another object of an embodiment of the invention can be to dispose of water in a manner which substantially eliminates the long term problems of water production during the production life of an oil or gas well.
Another object of an embodiment of the invention can be to provide an accelerated water evaporation system that can be cost effective both with respect to operation but also with respect to maintenance.
Naturally, further independent objects of the invention are disclosed throughout other areas of the specification.